Venture through the vast front door of Casa Bures and a life-size statue of a bear, sadly ­lacking its front paws — believed to have been stolen by looters — greets visitors at the foot of an ­ornately carved and cantilevered staircase.

A grand dome of stained glass covers a central atrium, throwing coloured light down on to the stonework. And the first-floor entertaining rooms in what was once one of the grandest private homes in Barcelona feature a mass of frescoes, murals, gilt walls, mosaics, marble columns, cornicing, carved panelling, and exquisite bas-relief sculpture.

Casa Bures, in the upscale Eixample neighbourhood, hasn’t been lived in (legally) since the 1980s. Now it is undergoing renovations to create 26 luxury apartments full of the modernista style pioneered by Spain’s totemic architect, Antoni Gaudi.

And despite Spain’s dismal property market, foreign buyers are ready to own a piece of Barcelona’s ­architectural history.

Superficially, there is little to distinguish Casa Bures, built for textiles magnate Francesc Bures, from the other historic mansions in the neighbourhood.

“From the outside this is a building which appears very normal,” said architect Juan Trias de Bes, at TDB Arquitectura, who is overseeing the renovation.

“All that is unusual is on the ­inside.”

Starting in 1900, it took five years for Casa Bures to take shape under the direction of one of Gaudi’s collaborators, the master builder Francesc Berenguer I Mestres. (The pair worked together on both the Palace Guell and Sagrada Familia.)

“The inspiration was craft and nature,” said Mr Trias de Bes, pointing to a heavy emphasis on images of animals, flowers, and woodland scenes (plus a full-scale Hansel and Gretel mural in one room), as well as the large number of artisan craftsmen required to make such a house.

Casa Bures wasn’t just a family home, but a live-work space. It was once common for even the wealthiest families in Barcelona to treat their properties as business opportunities, and the ground floor housed a textile factory, producing the linens that made Francesc Bures’ fortune. The family lived on the floor above, while the floors above them were rented as apartments.

Mr Bures was only able to enjoy his modernista home for two years. He died in 1907 and his family took over both the house and his company, Industrias Bures. In the 1980s, their descendants sold the home to the regional government of Catalonia, and in 2014 it was sold to developer Marcus Donaldson, partner at Bonavista Developments.

The building sold for $US20 million ($26.8m), while the renovations are costing an additional $US11m.

“It was fundamentally a ruin,” said Mr Donaldson. “There had been squatters living there who had trashed it, and a lot of the features, like very ornate ceilings, had been removed or covered over. We are always discovering new things — recently we found original gold-leaf paint under about four layers of wallpaper.”

As well as restoring original features the project has involved dividing Casa Bures into five penthouses and 21 apartments. When complete in 2017, it will also have a rooftop swimming pool, a second pool in the basement, workout facilities, private dining rooms and a wine cellar.

Prices start at $US1.1m for a one-bedroom apartment of 120sq m, up to a four-bedroom apartment at 500sq m at $US6.78m.